feat: implement email digest (#371)

prisma/migrations/20260429000000_add_email_digest/migration.sql

@@ -0,0 +1,32 @@
+-- CreateEnum
+CREATE TYPE "DigestFrequency" AS ENUM ('DAILY', 'WEEKLY');
+
+-- CreateTable
+CREATE TABLE "digest_preferences" (
+    "id" TEXT NOT NULL,
+    "user_id" TEXT NOT NULL,
+    "frequency" "DigestFrequency" NOT NULL DEFAULT 'DAILY',
+    "enabled" BOOLEAN NOT NULL DEFAULT true,
+    "unsubscribe_token" TEXT NOT NULL,
+    "last_sent_at" TIMESTAMP(3),
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "digest_preferences_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "digest_preferences_user_id_key" ON "digest_preferences"("user_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "digest_preferences_unsubscribe_token_key" ON "digest_preferences"("unsubscribe_token");
+
+-- CreateIndex
+CREATE INDEX "digest_preferences_user_id_idx" ON "digest_preferences"("user_id");
+
+-- CreateIndex
+CREATE INDEX "digest_preferences_enabled_frequency_idx" ON "digest_preferences"("enabled", "frequency");
+
+-- AddForeignKey
+ALTER TABLE "digest_preferences" ADD CONSTRAINT "digest_preferences_user_id_fkey"
+    FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;

prisma/schema.prisma

@@ -127,6 +127,11 @@ enum BounceType {
   SOFT
 }
 
+enum DigestFrequency {
+  DAILY
+  WEEKLY
+}
+
 
 // User model
 model User {
@@ -192,6 +197,7 @@ model User {
   linkClicks              LinkClick[]
   emailEngagements        EmailEngagement[]
   emailBounces            EmailBounce[]
+  digestPreference        DigestPreference?
 
 
   @@index([email])
@@ -760,3 +766,20 @@ model EmailBounce {
   @@map("email_bounces")
 }
 
+
+model DigestPreference {
+  id               String          @id @default(uuid())
+  userId           String          @unique @map("user_id")
+  frequency        DigestFrequency @default(DAILY)
+  enabled          Boolean         @default(true)
+  unsubscribeToken String          @unique @map("unsubscribe_token")
+  lastSentAt       DateTime?       @map("last_sent_at")
+  createdAt        DateTime        @default(now()) @map("created_at")
+  updatedAt        DateTime        @updatedAt @map("updated_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@index([userId])
+  @@index([enabled, frequency])
+  @@map("digest_preferences")
+}

src/app.module.ts

@@ -25,6 +25,7 @@ import { SearchModule } from './search/search.module';
 import { BackupModule } from './backup/backup.module';
 import { TrackingModule } from './tracking/tracking.module';
 import { NotificationsModule } from './notifications/notifications.module';
+import { EmailDigestModule } from './email-digest/email-digest.module';
 @Module({
   imports: [
     ConfigModule.forRoot({
@@ -60,6 +61,7 @@ import { NotificationsModule } from './notifications/notifications.module';
     BackupModule,
     TrackingModule,
     NotificationsModule,
+    EmailDigestModule,
   ],
   controllers: [AppController],
 })

src/email-digest/digest.scheduler.ts

@@ -0,0 +1,25 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { Cron, CronExpression } from '@nestjs/schedule';
+import { EmailDigestService } from './email-digest.service';
+import { DigestFrequency } from '@prisma/client';
+
+@Injectable()
+export class DigestScheduler {
+  private readonly logger = new Logger(DigestScheduler.name);
+
+  constructor(private readonly emailDigestService: EmailDigestService) {}
+
+  // Every day at 8:00 AM UTC
+  @Cron('0 8 * * *')
+  async runDailyDigest() {
+    this.logger.log('Running daily digest...');
+    await this.emailDigestService.sendDigestsForFrequency(DigestFrequency.DAILY);
+  }
+
+  // Every Monday at 8:00 AM UTC
+  @Cron('0 8 * * 1')
+  async runWeeklyDigest() {
+    this.logger.log('Running weekly digest...');
+    await this.emailDigestService.sendDigestsForFrequency(DigestFrequency.WEEKLY);
+  }
+}

src/email-digest/dto/update-digest-preference.dto.ts

@@ -0,0 +1,12 @@
+import { IsEnum, IsBoolean, IsOptional } from 'class-validator';
+import { DigestFrequency } from '@prisma/client';
+
+export class UpdateDigestPreferenceDto {
+  @IsOptional()
+  @IsEnum(DigestFrequency)
+  frequency?: DigestFrequency;
+
+  @IsOptional()
+  @IsBoolean()
+  enabled?: boolean;
+}

src/email-digest/email-digest.controller.ts

@@ -0,0 +1,35 @@
+import { Body, Controller, Get, Param, Patch, Query, Res, UseGuards } from '@nestjs/common';
+import { Response } from 'express';
+import { EmailDigestService } from './email-digest.service';
+import { UpdateDigestPreferenceDto } from './dto/update-digest-preference.dto';
+import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
+import { CurrentUser } from '../auth/decorators/current-user.decorator';
+
+@Controller('email-digest')
+export class EmailDigestController {
+  constructor(private readonly emailDigestService: EmailDigestService) {}
+
+  @UseGuards(JwtAuthGuard)
+  @Get('preference')
+  getPreference(@CurrentUser() user: { id: string }) {
+    return this.emailDigestService.getOrCreatePreference(user.id);
+  }
+
+  @UseGuards(JwtAuthGuard)
+  @Patch('preference')
+  updatePreference(
+    @CurrentUser() user: { id: string },
+    @Body() dto: UpdateDigestPreferenceDto,
+  ) {
+    return this.emailDigestService.updatePreference(user.id, dto);
+  }
+
+  @Get('unsubscribe')
+  async unsubscribe(@Query('token') token: string, @Res() res: Response) {
+    const success = await this.emailDigestService.unsubscribeByToken(token);
+    const message = success
+      ? 'You have been unsubscribed from PropChain email digests.'
+      : 'Invalid or expired unsubscribe link.';
+    return res.send(`<html><body style="font-family:Arial;text-align:center;padding:40px"><h2>${message}</h2></body></html>`);
+  }
+}

src/email-digest/email-digest.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common';
+import { EmailDigestService } from './email-digest.service';
+import { EmailDigestController } from './email-digest.controller';
+import { DigestScheduler } from './digest.scheduler';
+import { PrismaModule } from '../database/prisma.module';
+import { EmailModule } from '../email/email.module';
+
+@Module({
+  imports: [PrismaModule, EmailModule],
+  controllers: [EmailDigestController],
+  providers: [EmailDigestService, DigestScheduler],
+  exports: [EmailDigestService],
+})
+export class EmailDigestModule {}

src/email-digest/email-digest.service.ts

@@ -0,0 +1,157 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { PrismaService } from '../database/prisma.service';
+import { EmailService } from '../email/email.service';
+import { v4 as uuidv4 } from 'uuid';
+import { DigestFrequency } from '@prisma/client';
+import { ConfigService } from '@nestjs/config';
+
+@Injectable()
+export class EmailDigestService {
+  private readonly logger = new Logger(EmailDigestService.name);
+
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly emailService: EmailService,
+    private readonly configService: ConfigService,
+  ) {}
+
+  async getOrCreatePreference(userId: string) {
+    return this.prisma.digestPreference.upsert({
+      where: { userId },
+      update: {},
+      create: {
+        userId,
+        frequency: DigestFrequency.DAILY,
+        enabled: true,
+        unsubscribeToken: uuidv4(),
+      },
+    });
+  }
+
+  async updatePreference(
+    userId: string,
+    data: { frequency?: DigestFrequency; enabled?: boolean },
+  ) {
+    return this.prisma.digestPreference.upsert({
+      where: { userId },
+      update: data,
+      create: {
+        userId,
+        frequency: data.frequency ?? DigestFrequency.DAILY,
+        enabled: data.enabled ?? true,
+        unsubscribeToken: uuidv4(),
+      },
+    });
+  }
+
+  async unsubscribeByToken(token: string): Promise<boolean> {
+    const pref = await this.prisma.digestPreference.findUnique({
+      where: { unsubscribeToken: token },
+    });
+    if (!pref) return false;
+
+    await this.prisma.digestPreference.update({
+      where: { unsubscribeToken: token },
+      data: { enabled: false },
+    });
+    return true;
+  }
+
+  async sendDigestsForFrequency(frequency: DigestFrequency): Promise<void> {
+    const prefs = await this.prisma.digestPreference.findMany({
+      where: { frequency, enabled: true },
+      include: { user: { select: { id: true, email: true, firstName: true, emailStatus: true } } },
+    });
+
+    const since = this.getSinceDate(frequency);
+
+    for (const pref of prefs) {
+      if (pref.user.emailStatus === 'INVALID') continue;
+
+      try {
+        await this.sendDigestForUser(pref.user, since, pref.unsubscribeToken);
+        await this.prisma.digestPreference.update({
+          where: { id: pref.id },
+          data: { lastSentAt: new Date() },
+        });
+      } catch (err) {
+        this.logger.error(`Failed to send digest to ${pref.user.email}: ${err.message}`);
+      }
+    }
+  }
+
+  private async sendDigestForUser(
+    user: { id: string; email: string; firstName: string },
+    since: Date,
+    unsubscribeToken: string,
+  ): Promise<void> {
+    const notifications = await this.prisma.notification.findMany({
+      where: { userId: user.id, createdAt: { gte: since } },
+      orderBy: { createdAt: 'desc' },
+      take: 50,
+    });
+
+    if (notifications.length === 0) return;
+
+    const apiUrl = this.configService.get<string>('API_URL', 'http://localhost:3000/api');
+    const unsubscribeUrl = `${apiUrl}/email-digest/unsubscribe?token=${unsubscribeToken}`;
+
+    const html = this.buildDigestHtml(user.firstName, notifications, unsubscribeUrl);
+
+    await this.emailService['sendEmail']({
+      to: user.email,
+      subject: `Your PropChain Digest – ${notifications.length} update${notifications.length > 1 ? 's' : ''}`,
+      html,
+      userId: user.id,
+      emailType: 'digest',
+    });
+  }
+
+  private buildDigestHtml(
+    firstName: string,
+    notifications: Array<{ title: string; message: string; type: string; createdAt: Date }>,
+    unsubscribeUrl: string,
+  ): string {
+    const rows = notifications
+      .map(
+        (n) => `
+        <tr>
+          <td style="padding:12px 0;border-bottom:1px solid #eee;">
+            <strong style="color:#333;">${n.title}</strong>
+            <span style="display:inline-block;margin-left:8px;padding:2px 8px;background:#f0f4ff;color:#4a6cf7;border-radius:12px;font-size:12px;">${n.type}</span>
+            <p style="margin:4px 0 0;color:#666;font-size:14px;">${n.message}</p>
+            <small style="color:#999;">${new Date(n.createdAt).toLocaleString()}</small>
+          </td>
+        </tr>`,
+      )
+      .join('');
+
+    return `
+      <div style="font-family:Arial,sans-serif;max-width:600px;margin:0 auto;color:#333;">
+        <div style="background:#4a6cf7;padding:24px;border-radius:8px 8px 0 0;">
+          <h1 style="color:#fff;margin:0;font-size:22px;">PropChain Digest</h1>
+        </div>
+        <div style="padding:24px;background:#fff;border:1px solid #eee;border-top:none;">
+          <p>Hi ${firstName},</p>
+          <p>Here's a summary of your recent notifications:</p>
+          <table style="width:100%;border-collapse:collapse;">${rows}</table>
+        </div>
+        <div style="padding:16px;background:#f9f9f9;border:1px solid #eee;border-top:none;border-radius:0 0 8px 8px;text-align:center;">
+          <small style="color:#999;">
+            You're receiving this because you subscribed to PropChain digests.
+            <a href="${unsubscribeUrl}" style="color:#4a6cf7;">Unsubscribe</a>
+          </small>
+        </div>
+      </div>`;
+  }
+
+  private getSinceDate(frequency: DigestFrequency): Date {
+    const now = new Date();
+    if (frequency === DigestFrequency.WEEKLY) {
+      now.setDate(now.getDate() - 7);
+    } else {
+      now.setDate(now.getDate() - 1);
+    }
+    return now;
+  }
+}